1. Field of the Invention
The invention relates in general to a circuit interrupter operating mechanism and in particular to a chemical operator drive means having a stationary piston and a movable drive cylinder.
2. Description of the Prior Art
Modern circuit interrupter operating drive mechanisms may employ a chemical operator drive mechanism comprising a chemical gas generator which ignites a propellant charge of expulsive material to propel a high pressure gaseous medium through a conduit into a drive piston and cylinder assembly. When the chemical propellant drive mechanism is used for both the opening and closing of the circuit interrupter contacts an inherent problem plagues the piston cylinder assembly, namely destruction of the shaft seal. In a combustion device such as a chemical propellant mechanism, combustion produces residues which deposit on the piston drive rod and creates the problems of abrasion and "gumming" for the piston rod shaft seal. Accordingly, it would be desirable to have a drive mechanism piston cylinder assembly which would not require piston rod shaft seal.